i have questions, please give me answers i am DESPERATE😭

I was diagnosed with pcos a few months ago and I was told that if I wanted to get pregnant I have to track down my ovulation the best I could.. I never had to do that before because when I had my son I thought I was done having babies and 5 years later... well here I am.

my question is, how do I keep track of it? what is there do be done? please help me.. every damn bfn I get is just heartbreaking.. I am so close to just giving up ttc, but i figure that one more shot at it won't hurt. thanks in advance and baby dust to all ❤️